1. Field of the Invention
The present invention relates to a valve for controlling fluid flow. One function of the valve is to allow injection of fluid from a source exterior to the valve to within the valve interior.
2. Description of the Prior Art
The embodiments of the present invention shown within the application are especially adapted for use within a wireline lubricator for servicing oil and gas wells. U.S. Pat. No. 3,831,676 to Vernon L. Brown and Joseph L. Pearce discloses a stuffing box for attachment to a lubricator to seal around a wireline. U.S. Pat. No. 3,762,725 to Donald F. Taylor discloses a stuffing box and a sealing gland which uses hydraulic fluid to vary the force with which the sealing gland engages a wireline disposed therein. Both patents provide details concerning the use of wireline lubricators and are incorporated by reference for all purposes within this application.